In Islam the jinn (traditionally translated into English 'genie') are beings made of fire. Some are good and some are evil. They are not, however, the same as angels (malaa'ik) or demons (shayatiin). Here is great question from a reader of Islam Question and Answer (islamqa.com):
Question:
Is there any real contact between humans and jinn? Is it true that a jinni can possess a person and speak on his lips, or not?.
Answer:
Praise be to Allaah.
[...]
To sum up: it is proven that the jinn can harm humans by possessing them, and this is indicated by the Qur’aan and by visible experience that no one can deny but one who is ignorant.
The best means of dealing with that is reciting Qur’aan over the one who is affected, and treating him with ruqyah that contains du’aa’s narrated from the Prophet (peace and blessings of Allaah be upon him), and what he is suffering will disappear, in sha Allaah.
As for what some charlatans and liars do nowadays, such as prescribing some du’aa’s and drinks, claiming that this will bring the jinni out of the body of the person, the basic principle is that this is haraam and it is not permissible to treat such cases except with du’aa’s from Qur’aan and Sunnah. End quote.
(Abu Daoud says: This is of course related to the infamous instance of the Satanic Verses when Muhammad says that Satan [who is not a jinn] placed certain words upon his lips, though at the time he had thought the words were from Gabriel.)
